From f5c37135f7309db8401837e381f85217550f7d5c Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Thu, 7 Nov 2013 08:41:27 +0100 Subject: [PATCH] usb: gadget: f_loopback: add configfs support Add support for using the loopback USB function in gadgets composed with configfs. Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Kyungmin Park Signed-off-by: Felipe Balbi --- .../ABI/testing/configfs-usb-gadget-loopback | 8 ++ drivers/usb/gadget/Kconfig | 12 ++ drivers/usb/gadget/f_loopback.c | 132 +++++++++++++++++++++ drivers/usb/gadget/g_zero.h | 12 ++ drivers/usb/gadget/zero.c | 4 +- 5 files changed, 166 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-loopback diff --git a/Documentation/ABI/testing/configfs-usb-gadget-loopback b/Documentation/ABI/testing/configfs-usb-gadget-loopback new file mode 100644 index 0000000..852b236 --- /dev/null +++ b/Documentation/ABI/testing/configfs-usb-gadget-loopback @@ -0,0 +1,8 @@ +What: /config/usb-gadget/gadget/functions/Loopback.name +Date: Nov 2013 +KenelVersion: 3.13 +Description: + The attributes: + + qlen - depth of loopback queue + bulk_buflen - buffer length diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index 93dfc90..6baddd5 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -687,6 +687,18 @@ config USB_CONFIGFS_MASS_STORAGE device (in much the same way as the "loop" device driver), specified as a module parameter or sysfs option. +config USB_CONFIGFS_F_LB + boolean "Loopback function (for testing)" + depends on USB_CONFIGFS + select USB_F_SS_LB + help + It loops back a configurable number of transfers. + It also implements control requests, for "chapter 9" conformance. + Make this be the first driver you try using on top of any new + USB peripheral controller driver. Then you can use host-side + test software, like the "usbtest" driver, to put your hardware + and its driver through a basic set of functional tests. + config USB_ZERO tristate "Gadget Zero (DEVELOPMENT)" select USB_LIBCOMPOSITE diff --git a/drivers/usb/gadget/f_loopback.c b/drivers/usb/gadget/f_loopback.c index b790653..c35bb40 100644 --- a/drivers/usb/gadget/f_loopback.c +++ b/drivers/usb/gadget/f_loopback.c @@ -231,6 +231,14 @@ autoconf_fail: static void lb_free_func(struct usb_function *f) { + struct f_lb_opts *opts; + + opts = container_of(f->fi, struct f_lb_opts, func_inst); + + mutex_lock(&opts->lock); + opts->refcnt--; + mutex_unlock(&opts->lock); + usb_free_all_descriptors(f); kfree(func_to_loop(f)); } @@ -386,6 +394,11 @@ static struct usb_function *loopback_alloc(struct usb_function_instance *fi) return ERR_PTR(-ENOMEM); lb_opts = container_of(fi, struct f_lb_opts, func_inst); + + mutex_lock(&lb_opts->lock); + lb_opts->refcnt++; + mutex_unlock(&lb_opts->lock); + buflen = lb_opts->bulk_buflen; qlen = lb_opts->qlen; if (!qlen) @@ -402,6 +415,118 @@ static struct usb_function *loopback_alloc(struct usb_function_instance *fi) return &loop->function; } +static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_lb_opts, + func_inst.group); +} + +CONFIGFS_ATTR_STRUCT(f_lb_opts); +CONFIGFS_ATTR_OPS(f_lb_opts); + +static void lb_attr_release(struct config_item *item) +{ + struct f_lb_opts *lb_opts = to_f_lb_opts(item); + + usb_put_function_instance(&lb_opts->func_inst); +} + +static struct configfs_item_operations lb_item_ops = { + .release = lb_attr_release, + .show_attribute = f_lb_opts_attr_show, + .store_attribute = f_lb_opts_attr_store, +}; + +static ssize_t f_lb_opts_qlen_show(struct f_lb_opts *opts, char *page) +{ + int result; + + mutex_lock(&opts->lock); + result = sprintf(page, "%d", opts->qlen); + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_lb_opts_qlen_store(struct f_lb_opts *opts, + const char *page, size_t len) +{ + int ret; + u32 num; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto end; + } + + ret = kstrtou32(page, 0, &num); + if (ret) + goto end; + + opts->qlen = num; + ret = len; +end: + mutex_unlock(&opts->lock); + return ret; +} + +static struct f_lb_opts_attribute f_lb_opts_qlen = + __CONFIGFS_ATTR(qlen, S_IRUGO | S_IWUSR, + f_lb_opts_qlen_show, + f_lb_opts_qlen_store); + +static ssize_t f_lb_opts_bulk_buflen_show(struct f_lb_opts *opts, char *page) +{ + int result; + + mutex_lock(&opts->lock); + result = sprintf(page, "%d", opts->bulk_buflen); + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_lb_opts_bulk_buflen_store(struct f_lb_opts *opts, + const char *page, size_t len) +{ + int ret; + u32 num; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto end; + } + + ret = kstrtou32(page, 0, &num); + if (ret) + goto end; + + opts->bulk_buflen = num; + ret = len; +end: + mutex_unlock(&opts->lock); + return ret; +} + +static struct f_lb_opts_attribute f_lb_opts_bulk_buflen = + __CONFIGFS_ATTR(buflen, S_IRUGO | S_IWUSR, + f_lb_opts_bulk_buflen_show, + f_lb_opts_bulk_buflen_store); + +static struct configfs_attribute *lb_attrs[] = { + &f_lb_opts_qlen.attr, + &f_lb_opts_bulk_buflen.attr, + NULL, +}; + +static struct config_item_type lb_func_type = { + .ct_item_ops = &lb_item_ops, + .ct_attrs = lb_attrs, + .ct_owner = THIS_MODULE, +}; + static void lb_free_instance(struct usb_function_instance *fi) { struct f_lb_opts *lb_opts; @@ -417,7 +542,14 @@ static struct usb_function_instance *loopback_alloc_instance(void) lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL); if (!lb_opts) return ERR_PTR(-ENOMEM); + mutex_init(&lb_opts->lock); lb_opts->func_inst.free_func_inst = lb_free_instance; + lb_opts->bulk_buflen = GZERO_BULK_BUFLEN; + lb_opts->qlen = GZERO_QLEN; + + config_group_init_type_name(&lb_opts->func_inst.group, "", + &lb_func_type); + return &lb_opts->func_inst; } DECLARE_USB_FUNCTION(Loopback, loopback_alloc_instance, loopback_alloc); diff --git a/drivers/usb/gadget/g_zero.h b/drivers/usb/gadget/g_zero.h index a1c1a97..19ec50a42 100644 --- a/drivers/usb/gadget/g_zero.h +++ b/drivers/usb/gadget/g_zero.h @@ -6,6 +6,9 @@ #ifndef __G_ZERO_H #define __G_ZERO_H +#define GZERO_BULK_BUFLEN 4096 +#define GZERO_QLEN 32 + struct usb_zero_options { unsigned pattern; unsigned isoc_interval; @@ -30,6 +33,15 @@ struct f_lb_opts { struct usb_function_instance func_inst; unsigned bulk_buflen; unsigned qlen; + + /* + * Read/write access to configfs attributes is handled by configfs. + * + * This is to protect the data from concurrent access by read/write + * and create symlink/remove symlink. + */ + struct mutex lock; + int refcnt; }; void lb_modexit(void); diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c index 4be2f4b..c2ed959 100644 --- a/drivers/usb/gadget/zero.c +++ b/drivers/usb/gadget/zero.c @@ -66,8 +66,8 @@ module_param(loopdefault, bool, S_IRUGO|S_IWUSR); static struct usb_zero_options gzero_options = { .isoc_interval = 4, .isoc_maxpacket = 1024, - .bulk_buflen = 4096, - .qlen = 32, + .bulk_buflen = GZERO_BULK_BUFLEN, + .qlen = GZERO_QLEN, }; /*-------------------------------------------------------------------------*/ -- 2.7.4